1. Field of the Invention
The present invention relates to an OFDM (Orthogonal Frequency Division Multiplex) system, a symbol estimating apparatus and an inter-carrier interference cancellation method, and more particularly, to an OFDM (Orthogonal Frequency Division Multiplex) system, a symbol estimating apparatus and an inter-carrier interference cancellation method for estimating a symbol value using the output of a forward error correction decoder.
2. Description of the Related Art
An OFDM system has an advantage of reducing the complexity of equalizer because it uses a 1-tap equalizer. However in an environment having an abrupt channel variation such as a rapidly moving receiver such as a cellphone in a moving automobile, a channel impulse response varies even during the brief period while a single OFDM symbol is transmitted. Accordingly, inter-carrier interference occurs and inter-carrier orthogonality is not secured. In this case, the 1-tap equalizer cannot perform channel equalization.
To remove the inter-carrier interference a multi-tap equalizer can be used. However, a matrix having a size corresponding to the number of carriers must be inversely transformed in order to apply the multi-tap equalizer for all the carriers of an OFDM symbol. This greatly increases the complexity of the equalizer.